This document provides a summary of a panel discussion on deploying DNSSEC from end customers to content. The panel discusses next steps that top-level domain operators, network operators, and enterprises can take to deploy DNSSEC, including signing their domains, accepting DS records, working with registrars, and deploying validating DNS resolvers. The Internet Society's Deploy360 program is also introduced, which provides real-world deployment information on technologies like DNSSEC through case studies, tutorials, videos, and other resources.

1. Deploying DNSSEC: From End-Customer To
Content
March 28, 2013
www.internetsociety.org

2. Our Panel
Moderator:
• Dan York, Senior Content Strategist, Internet Society
Panelists:
• Sanjeev Gupta, Principal Technical Architect, DCS1 Pte
• Jitender Kumar, Technical Account Manager, Afilias
• Richard Lamb, DNSSEC Program Manager, ICANN
www.internetsociety.org/deploy360/

3. A Quick Introduction to DNS and DNSSEC

4. What Problem Is DNSSEC Trying To Solve?
DNSSEC = "DNS Security Extensions"
• Defined in RFCs 4033, 4034, 4035
• Operational Practices: RFC 4641
Ensures that the information entered into DNS by the
domain name holder is the SAME information retrieved
from DNS by an end user.
Let's walk through an example to explain…
www.internetsociety.org/deploy360/

5. A Normal DNS Interaction
Web
Server
example.com? Resolver checks its local cache. If it has the
3 DNS answer, it sends it back.
1
https://example.com/ Resolver
example.com 10.1.1.123
4 If not…
web page Web
Browser 2
10.1.1.123
www.internetsociety.org/deploy360/

6. A Normal DNS Interaction DNS Svr
root
.com
NS
DNS Svr
.com
Web example.com
NS
Server
example.com?
5 DNS 2
https://example.com/
1
Resolver DNS Svr
example.com
3
6
10.1.1.123
web page Web
Browser 4
10.1.1.123
www.internetsociety.org/deploy360/

7. DNS Works On Speed
First result received by a DNS resolver is treated as the
correct answer.
Opportunity is there for an attacker to be the first one to
get an answer to the DNS resolver, either by:
• Getting to the correct point in the network to provide faster responses;
• Blocking the responses from the legitimate servers (ex. executing a
Denial of Service attack against the legitimate servers to slow their
responses)
www.internetsociety.org/deploy360/

8. Attacking DNS DNS Svr
root
.com
NS
DNS Svr
.com
Web example.com
NS
Server
example.com?
5 DNS 2
https://example.com/
1
Resolver DNS Svr
example.com
10.1.1.123
6
web page Web 3
Browser 4
192.168.2.2
Attacking
192.168.2.2 DNS Svr
example.com
www.internetsociety.org/deploy360/

9. A Poisoned Cache
Web
Server
example.com? Resolver cache now has wrong data:
3 DNS
1 example.com 192.168.2.2
https://example.com/ Resolver
4
This stays in the cache until the
web page Web Time-To-Live (TTL) expires!
Browser 2
192.168.2.2
www.internetsociety.org/deploy360/

10. How Does DNSSEC Help?
DNSSEC introduces new DNS records for a domain:
• RRSIG – a signature ("hash") of a set of DNS records
• DNSKEY – a public key that a resolver can use to validate RRSIG
A DNSSEC-validating DNS resolver:
• Uses DNSKEY to perform a hash calculation on received DNS records
• Compares result with RRSIG records. If results match, records are the
same as those transmitted. If the results do NOT match, they were
potentially changed during the travel from the DNS server.
www.internetsociety.org/deploy360/

11. A DNSSEC Interaction DNS Svr
root
DNS Svr
.com
Web
Server
example.com?
5 DNS 2
https://example.com/
1
Resolver DNS Svr
example.com
3
6
10.1.1.123
web page Web DNSKEY
RRSIGs
Browser 4
10.1.1.123
www.internetsociety.org/deploy360/

12. But Can DNSSEC Be Spoofed?
• But why can't an attacker simply insert DNSKEY and
RRSIG records? What prevents DNSSEC from being
spoofed?
• An additional was introduced, the "Delegation Signer
(DS)" record
• It is a fingerprint of the DNSKEY record that is sent to
the TLD registry
• Provides a global "chain of trust" from the root of
DNS down to the domain
• Attackers would have to compromise the registry
www.internetsociety.org/deploy360/

13. A DNSSEC Interaction DNS Svr
root
.com
NS
DS
DNS Svr
.com
Web example.com
NS
Server DS
example.com?
5 DNS 2
https://example.com/
1
Resolver DNS Svr
example.com
3
6
10.1.1.123
web page Web DNSKEY
RRSIGs
Browser 4
10.1.1.123
www.internetsociety.org/deploy360/

14. The Global Chain of Trust DNS Svr
root
.com
NS
DS
DNS Svr
.com
Web example.com
NS
Server DS
example.com?
5 DNS 2
https://example.com/
1
Resolver DNS Svr
example.com
3
6
10.1.1.123
web page Web DNSKEY
RRSIGs
Browser 4
10.1.1.123
www.internetsociety.org/deploy360/

15. Attempting to Spoof DNS DNS Svr
root
.com
NS
DS
DNS Svr
.com
Web example.com
NS
Server DS
example.com?
5 DNS 2
https://example.com/
1
Resolver DNS Svr
example.com
10.1.1.123
6 DNSKEY
RRSIGs
web page Web 3
Browser
Attacking
192.168.2.2 DNS Svr
DNSKEY example.com
RRSIGs
www.internetsociety.org/deploy360/

16. Attempting to Spoof DNS DNS Svr
root
.com
NS
DS
DNS Svr
.com
Web example.com
NS
Server DS
example.com?
5 DNS 2
https://example.com/
1
Resolver DNS Svr
example.com
10.1.1.123
6 DNSKEY
RRSIGs
web page Web 3
Browser 4
SERVFAIL
Attacking
192.168.2.2 DNS Svr
DNSKEY example.com
RRSIGs
www.internetsociety.org/deploy360/

17. What DNSSEC Proves:
"These ARE the IP addresses you are looking for."
(or they are not)
Ensures that information entered into DNS by the domain
name holder (or the operator of the DNS hosting service for
the domain) is the SAME information that is received by the
end user.
www.internetsociety.org/deploy360/

18. The Two Parts of DNSSEC
Signing Validating
Registries Applications
Registrars Enterprises
DNS Hosting ISPs
www.internetsociety.org/deploy360/

19. DNSSEC and SSL

20. Why Do I Need DNSSEC If I Have SSL?
A common question: why do I need DNSSEC if I already
have a SSL certificate? (or an "EV-SSL" certificate?)
SSL (more formerly known today as Transport Layer
Security (TLS)) solves a different issue – it provides
encryption and protection of the communication between the
browser and the web server
www.internetsociety.org/deploy360/

21. The Typical TLS (SSL) Web Interaction DNS Svr
root
Web
Server
DNS Svr
.com
5
https://example.com/
DNS Svr
6 example.com
TLS-encrypted
web page
2
example.com?
3
1 10.1.1.123
DNS
Resolver
Web
Browser 4
10.1.1.123
www.internetsociety.org/deploy360/

22. The Typical TLS (SSL) Web Interaction DNS Svr
root
Web
Server
DNS Svr
.com
5
https://example.com/
DNS Svr
6 example.com
TLS-encrypted
web page
2
example.com?
3
1 10.1.1.123
DNS
Is this encrypted Resolver
with the
Web
CORRECT Browser 4
certificate? 10.1.1.123
www.internetsociety.org/deploy360/

23. What About This?
DNS
Web Server
https://www.example.com/
Server
www.example.com?
Firewall https://www.example.com/
TLS-encrypted web page (or
1
with CORRECT certificate attacker) 1.2.3.4
2
Web
TLS-encrypted web page
Browser
with NEW certificate
(re-signed by firewall)
www.internetsociety.org/deploy360/

24. Problems?
DNS
Web Server
https://www.example.com/
Server
www.example.com?
https://www.example.com/
TLS-encrypted web page Firewall
1
with CORRECT certificate 1.2.3.4
2
Web
TLS-encrypted web page
Browser
with NEW certificate
(re-signed by firewall)
www.internetsociety.org/deploy360/

25. Problems?
DNS
Web Server
https://www.example.com/
Server
www.example.com?
https://www.example.com/
TLS-encrypted web page Firewall
1
with CORRECT certificate 1.2.3.4
2
Web
TLS-encrypted web page
Browser
with NEW certificate
Log files (re-signed by firewall)
or other
servers
Potentially including
personal information
www.internetsociety.org/deploy360/

26. Issues
A Certificate Authority (CA) can sign ANY domain.
Now over 1,500 CAs – there have been compromises
where valid certs were issued for domains.
Middle-boxes such as firewalls can re-sign sessions.
www.internetsociety.org/deploy360/

27. A Powerful Combination
TLS/SSL = encryption + limited integrity protection
DNSSEC = strong integrity protection
How to get encryption + strong integrity protection?
TLS + DNSSEC = DANE
www.internetsociety.org/deploy360/

28. DNS-Based Authentication of Named Entities
(DANE)
Q: How do you know if the TLS (SSL) certificate is the
correct one the site wants you to use?
A: Store the certificate (or fingerprint) in DNS (new TLSA
record) and sign them with DNSSEC.
A browser that understand DNSSEC and DANE will then
know when the required certificate is NOT being used.
Certificate stored in DNS is controlled by the domain name
holder. It could be a certificate signed by a CA – or a self-
signed certificate.
www.internetsociety.org/deploy360/

29. DANE
DNS
Web Server
https://example.com/
Server
example.com? 2
Firewall https://example.com/
TLS-encrypted web page (or
1
with CORRECT certificate attacker) 10.1.1.123
DNSKEY
RRSIGs
TLSA
Web
TLS-encrypted web page Browser
with NEW certificate w/DANE
Log files (re-signed by firewall)
or other
servers
DANE-equipped browser
compares TLS certificate
with what DNS / DNSSEC
says it should be.
www.internetsociety.org/deploy360/

30. DANE – Not Just For The Web
• DANE defines protocol for storing TLS certificates in DNS
• Securing Web transactions is the obvious use case
• Other uses also possible:
• Email via S/MIME
• VoIP
• Jabber/XMPP
• ?
www.internetsociety.org/deploy360/

31. DNSSEC Deployment In Asia

32. Map courtesy of Shinkuro, Inc.
www.internetsociety.org/deploy360/

33. Map courtesy of Shinkuro, Inc.
www.internetsociety.org/deploy360/

34. Panel Discussion

35. Our Panel
Moderator:
• Dan York, Senior Content Strategist, Internet Society
Panelists:
• Sanjeev Gupta, Principal Technical Architect, DCS1 Pte
• Jitender Kumar, Technical Account Manager, Afilias
• Richard Lamb, DNSSEC Program Manager, ICANN
www.internetsociety.org/deploy360/

36. Next Steps In Deploying DNSSEC

37. Three Steps TLD Operators Can Take:
1. Sign your TLD
• Tools and services available to help automate process
2. Accept DS records
• Make it as easy as possible (and accept multiple records)
3. Work with your registrars
• Help them make it easy for DNS hosting providers and registrants
4. Help With Statistics
• Can you help by providing statistics?
Implement DNSSEC and make your TLD more secure
www.internetsociety.org/deploy360/

38. Three Steps For Network Operators and
Enterprises
1. Deploy DNSSEC-validating DNS resolvers
2. Sign your own domains where possible
3. Help promote support of DANE protocol
• Allow usage of TLSA record. Let browser vendors and others know you
want to use DANE. Help raise awareness of how DANE and DNSSEC
can make the Internet more secure.
www.internetsociety.org/deploy360/

39. Internet Society Deploy360 Programme
Providing real-world deployment
info for IPv6, DNSSEC and other
Internet technologies:
• Case Studies
• Tutorials
• Videos
• Whitepapers
• News, information
English content, initially, but will
www.internetsociety.org/deploy360/ be translated into other
languages.
www.internetsociety.org/deploy360/

40. Dan York, CISSP
Senior Content Strategist, Internet Society
york@isoc.org
www.internetsociety.org/deploy360/
Thank You!
www.internetsociety.org